1. Field of the Invention
The present invention relates generally to a projecting device and the lens adjusting module thereof. Particularly, the present invention relates to a lens adjusting module capable of adjusting the position of lens and a projecting device having the same.
2. Description of the Prior Art
Among projectors in current markets, the lens module is generally fixed on the projector. If users want to adjust the position of the projected image on the screen, they have to change the relative position between the projector and the screen. Users must expend time and be patient to correctly adjust the position and angle of the projector so that the projected image on the screen is at optimal viewing.
After determining the position of the projector, if users want to heighten the projected image on the screen, they must adjust the front stands of the projector to increase the projection elevation angle. However, adjusting the height of the front stands will change the relative angle between the lens and the screen and result in image distortion. For example, a rectangular image projected previously is distorted in a trapezoidal fashion.
To resolve the mentioned problems, several lens adjusting devices for the projector have been developed. By adjusting the position of the lens, users can easily shift projected images up or down on the screen without image distortion effects.
For instance, Taiwan Patent Publication No. 200900836 illustrates a lens-shifting device of a projector, which discloses gear sets, a sliding plate, and fixing rods to smoothly and accurately move the lens disposed on the sliding plate along the fixing rod. In this manner, minute adjustment of the lens position can be achieved.
However, the prior art lens-adjusting device has an overly complicated design, making the adjusting device bulky, heavy, and cost ineffective. As a result, conventional lens-adjusting devices are not widely adopted in projectors targeted to miniaturization and personalization. Additionally, the projector structure would need to be heavily modified to accommodate the complicated design of the prior art lens-adjusting device, which causes that the projector cannot adapt to various types of lens. Therefore, the practicality is significantly restricted.